English is widely used as a common language in the world.

In chemistry class, I learned about the process of polymerization.

Through this chemical reaction, monomers polymerize to form polymers.

My room is twenty-five square meters.

During the war, he continued to support his family on the home front.

He is fifty years old and still full of energy.

Doublet is an important concept in linguistics.

My birthday is on the fifteenth.

My house is located to the east of Tokyo.

Higashi is my best friend.